M. Mahendra

Microwave assisted synthesis of dihydrobenzo[4,5]imidazo[1,2-a]pyrimidin-4-ones; synthesis, in vitro antimicrobial and anticancer activities of novel coumarin substituted dihydrobenzo[4,5]imidazo[1,2-a]pyrimidin-4-ones.

The present article describes the synthesis of dihydrobenzo[4,5]imidazo[1,2-a]pyrimidin-4-one (2a-h) under microwave irradiation. The product was obtained in excellent yield (74-94%) in a shorter reaction time (2 min). These molecules (2a, b) further reacted with various substituted 4-bromomethylcoumarins (3a-f) to yield a new series of coumarin substituted dihydrobenzo[4,5]imidazo[1,2-a]pyrimidin-4-ones (4a-h). The structure of all the synthesized compounds were confirmed by spectral studies and screened for their in vitro antibacterial activity against three Gram-positive bacteria viz., Staphylococcus aureus, Enterococcus faecalis, Streptococcus mutans and three Gram-negative bacteria viz., Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa and antifungal activity against Candida albicans, Aspergillus niger, Aspergillus fumigatus, Aspergillus flavus, Fusarium oxysporum, Penicillium chrysogenum and anticancer activity against Daltons Ascitic Lymphoma (DAL) cell line. In general, all the compounds possessed better antifungal properties than antibacterial properties. The coumarin substituted dihydrobenzo[4,5]imidazo[1,2-a]pyrimidin-4-one (4g) (R = i-Pr, R₁ = 6-Cl) was found to be the most potent cytotoxic compound (88%) against Daltons Ascitic Lymphoma cell line at the concentration of 100 μg/mL.

Hydrothermal synthesis, structure and characterization of new NASICON related potassium iron (III) pyrophosphate

A new potassium iron (III) pyrophosphate was synthesized by hydrothermal technique and characterized by X-ray studies. The compound crystallizes in a monoclinic space group,P21/c, with cell parameters,a = 7 365(2) Å,b = 10017(2) Å,c = 8.214(1) Å,β = 106.50(1)° andZ = 4. The structure has tunnel-type cavities and are congenial for ion transportation through them. The compound exhibits moderate thermal stability.

Synthesis of N1 and N2 coumarin substituted 1,2,3-triazole isomers via click chemistry approach

ABSTRACT The synthesis of N1 and N2 coumarin substituted 1,2,3-triazole isomers from terminal alkynes, sodium azide, and 4-bromomethylcoumarins in the presence of triethylamine as a base and CuI as a catalyst in good yield are reported. The molecular structure of compounds 3g and 5d are established by single-crystal analysis. GRAPHICAL ABSTRACT

Hydrothermal synthesis, crystal structure and characterisation of Na2ZnP2O7·HCl

Na{sub 2}ZnP{sub 2}O{sub 7}{center_dot}HCl single crystals were synthesised by hydrothermal technique and characterised by X-ray diffraction method. The compound crystallises in tetragonal system with space group P4{sub 1}2{sub 1}2 and cell parameters a=7.687(5) A, c=20.529(1) A, Z=8, having tunnel type of cavities in the structure. DTA study indicates that this compound is thermally fairly stable.

Synthesis and structural characterization of CsNiP crystal

CsNiP crystals were synthesized by hydrothermal technique and characterized by the X-ray diffraction method. This alkaline transition metal phosphide crystallizes in the hexagonal system with space groupP63/mmc and cell parameters,a = 7.173(2) Å,c = 5.944(9) Å,V = 264.87(7) Å3 andZ = 2. The final residual factor isR1 = 0.0362 for 206 reflections withI > 2σ(I).

(4-Methoxy­phen­yl)(2-methyl­phen­yl)methanone

In the title compound, C15H14O2, the dihedral angle between the two benzene rings is 56.34 (7)°.

3-(4-Meth­oxy­phen­yl)-5-methylisoxazole-4-carb­oxy­lic acid

In the title compound, C12H11NO4, the dihedral angle between the benzene and isoxazole rings is 42.52 (8)°. The carboxylic acid group is close to being coplanar with the isoxazole ring [dihedral angle = 5.3 (2)°]. In the crystal, inversion dimers linked by pairs of O—H⋯O hydrogen bonds generate R 2 2(8) loops.

Ethyl 5-methyl-3-phenyl-isoxazole-4-carboxyl-ate.

In the title compound, C13H13NO3, the dihedral angle between the phenyl and isoxazole rings is 43.40 (13)°. The ethoxycarbonyl group is rotated out of the plane of the isoxazole ring by 16.2 (13)°.

Synthesis and crystal structure studies of ethyl 5-methyl-1, 3-diphenyl-1H-pyrazole-4-carboxylate

The title compound, C19H18N2O2, was investigated by single crystal X-ray diffraction method. It crystallizes in monoclinic class under the space group P21/c with cell parameters a= 8.4593(4) A, b=15.6284(6) A, c=12.4579(5) A, α=90°, β=98.241(3)°, γ=90° and Z=2. The ethoxycarbonyl group is slightly twisted from the pyrazole ring, and adopts syn-periplanar conformation. The crystal structure is stabilized by intermolecular C-H….O hydrogen bonds, which help in stabilizing the crystal structure.

N′-Benzoyl-5-methyl-1,3-diphenyl-1H-pyrazole-4-carbohydrazide

In the title compound, C24H20N4O2, the pyrazole ring makes dihedral angles of 47.57 (10)° and 30.56 (11)° with its N-bound and C-bound phenyl groups, respectively. The C—N—N—C group that links the two carbonyls has a torsion angle of 81.5 (2)°. The torsion angles between the carbonyl groups and their adjacent pyrazole and phenyl rings are 125.89 (19) and 164.22 (17)°, respectively. In the crystal, pairs of molecules are linked by N—H⋯O hydrogen bonds into R 2 2(10) ring motifs, which in turn link to form chains that propagate parallel to the c-axis direction.